Lamp socket



LAMP SOCKET Filed March 23, 1932 Ihvehtoh' William. H. Rbwe, b5 Maya/6&1,

His Attorhes,

Patented Oct. 1, 1935 PATENT OFFICE LAMP SOCKET William H. Rowe, Oliftondale, Mass, assignor to General Electric Company, a corporation of New York Application March 23, 1932, Serial No. 600,739

3 Claims.

The present invention relates to lamp sockets and especially to series lamp sockets, such as are used for street lighting, although it is not limited thereto necessarily.

The object of the invention is to provide an improved construction and arrangement in a lamp socket of this type, and for a consideration of what I believe to be novel and my invention, attention is directed to the accompanying description and the claims appended thereto.

In the drawing, Fig. 1 is a sectional View of a series lamp socket embodying the invention; Fig. 2 is a bottom plan view thereof; and Fig. 3 is a perspective view, partly in section and partly broken away, of the metal parts of the socket.

Referring to the drawing, I indicates the socket shell or casing. It may be made of porcelain or other suitable insulating material or compound. It is open at one end 2 for the reception of an incandescent lamp, such end being flared outwardly somewhat, and it is closed at the other end by an integral wall or closure 3, provided with a central rectangular opening 4. In wall 3 on opposite sides of opening 4 are countersunk holes 5, four being shown in the present instance, for the reception of fastening screws, the nuts for the screws occupying the countersunk portions 6 of the holes, such countersunk portions being rectangular so as to hold the nuts from turning. In the inner wall of shell I are opposed longitudinal extending grooves or guideways I.

Inside shell I is a base 8 of suitable insulating material such as porcelain or compound, or the like. Base 8 carries all the metal par-ts of the socket comprising the screw shell 9 and the two socket prongs I and I I. Screw shell 9 has an inturned flange I2 which rests on base 8 and through which extend pairs of eyelets I3 and I4 for fastening the screw shell to the base. Underlying the heads of the eyelets inside the shell are metal links I5 which serve to reinforce and strengthen the connection between the shell and the base. Prongs III and II are provided with angular portions I 6 and I! which engage the surface of base 8. Eyelets I3 pass through openings in angular portion I6 for fastening prong It to base 8. Prong II is fastened to base 8 by eyelets I8. By the foregoing arrangement it will be seen that the screw shell and two socket prongs are all attached to base 8 by means of the six eyelets shown. Base 8 with the screw shell and prongs attached thereto thus form a unitary structure.

Prongs I 9 and II extend out through opening 4 and are adapted to be inserted into a series receptacle of known construction. The outer ends of prongs I9 and II are adapted to receive between them a usual form of film or disk out out as is well understood. The receptacle and 5 the film or disk cutout are not illustrated as they form no part of the present invention. The use of a socket as illustrated is well understood by those familiar with series lamp circuits. Prong I0 is provided with an extension I9 which ex- 10 tends along the side of screw shell 9 and at its end is provided with an inset portion which projects through an opening 2| in the side of shell 9. When a lamp base is screwed into screw shell 9 it makes direct electrical contact with 15 inset portion 29.

Socket prong II is provided with an extension 22 which extends through an opening 23 in the side of screw shell 9 and extends over base 8 to provide a center contact 24 with which the 2 center contact of the lamp engages when a lamp is screwed into the shell. Projecting from center contact 24 is a tongue 25 which projects beneath flange I2. It is housed in a recess 26 in base 8. Extension 22 is somewhat resilient 25 and when a lamp is not in the socket, tongue 25 is held in yielding engagement with flange I2, thus short circuiting the outer ends of the socket prongs I0 and I I. When a lamp is screwed into shell 9 the engagement of the center contact of the lamp with extension 22 forces it downward so as to move tongue 25 from engagement with shell flange I2.

The unitary structure comprising base 8, prongs I0 and I I, and screw shell 9, is fastened in position in shell or casing I by means of screws 21 on the ends of which are nuts 28 located in the countersunk portions 6 of opening 5- Screws 2'! pass through the eyelets I3 and I8 in base 8 and through the openings 5. By this construction the unitary structure comprising base 8, prongs I0 and I I, and screw shell 9 can be readily attached to or removed from shell or casing I by merely removing the holding screws 21 and passing base 8 with the attached parts out through open end 2. The sides of extensions I9 and 22 slide in grooves "I, thus positioning base 8 correctly relatively to casing I. By this means, either the shell or casing I, or the unitary structure referred to, can be' rep-laced in case it becomes damaged or broken. This is a thing of substantial advantage, from a practical standpoint in that often a shell or casing I, which is usually made of porcelain, may be broken. By being enabled to replace readily a damaged shell or casing with a new shell or casing,

the socket can be repaired, thus effecting a substantial saving, since otherwise the entire socket would have to be replaced.

When a lamp is screwed into the socket it will be seen that the base of thelamp'makes direct contact with the prong extension [9 and that the center contact of the lamp makes direct engagement with the prong extension 22.

By this arrangement, there are no mechanicalrconnections through which the current is carried in passing from the prongs l and l I to the base and center contacts of the lamp, since the extensions l9 and 22 provide a continuous metallic path for the current. This serves to reduce the voltage drop through the lamp socket to a' minimum, a feature of substantial importance in connection with a series lamp socket, since ordinarily the voltage drop across each lamp is relatively small and th a current is relatively large.

What I claim as new and desire to secure by Letters Patent of the United States is:

, wall of said screw shell for directly engaging the screw base of a lamp and also projecting through the center opening in said closure, and a conductive connection extending through said base from said screw shell to said second prong for establishing a multiple current path to the lamp'screw base. V

2. In a lamp socket, the combination of ar easing, a base mounted in said casing, a screw shell mounted on said base and provided with openings in its side and bottom walls respectively, a pair of contact prongs mounted on said base and pro- 10 jecting from said casing at one end thereof, an extension on one of said prongs projecting through said side wall opening into said shell and adapted to engage the screw base of a lamp, and an extension on the other of said prongs projecting through said bottom wall and. directly engaging the center contact of a lamp.

3. A lamp socket comprising a casing, a base mounted in said casing, a screw shell mounted on said base and provided with a flange and openings through its wall, a pair of contact prongs mounted on said base and projecting from said casing at one end thereof, an extension on one of said prongs projecting through an opening in said shell' to engage the screw base of the lamp, and an extension on the other of said prongs for projecting through another of said openings and normally engaging said flange to form a short-circuit through said socket and operable to break said circuit and engage the center contact of a lamp when the lamp is screwed into said shell,

WILLIAM H. ROWE. 

